What is an Immediately Invoked Function Expression (IIFE) and what problem did it solve before ES modules?

Question

JavaScript Professional — Medium

What is an Immediately Invoked Function Expression (IIFE) and what problem did it solve before ES modules?

Accepted Answer

An Immediately Invoked Function Expression (IIFE) is a function expression that executes immediately after definition. It solved the problem of global variable pollution by creating a local scope, preventing variable name collisions in script-based projects where all code shared the global namespace.